The scientists tabulated the models' anthropometric data: height, weight, and measurements for bust, waist, and hip. They calculated composite measures from these data: body mass index, waist:hip ratio, waist:bust ratio, bust:hip ratio, and an androgyny index that tracked the ration of the model's hip and bust (the slimmer the model, the higher the androgyny index).

The scientists discovered that, while the weight of the models was a near constant ("and hence may indicate a stable attractiveness cue"), the other measurements changed over time. Models increased in height and age; bust size and hip size decreased, while waist size increased. Composite measures of body shape captured the same trends: body mass index and bust:hip ratio decreased, while waist:hip ratio, waist:bust ratio, and androgyny index all increased.

Solely in the interests of scientific inquiry, of course, we present a (safe for work) sampling of recent Playboy centerfolds (courtesy AllPosters.com). Comparing these lovelies with this archive of centerfolds from 1960-2000 is left as an exercise for the reader.